Oil sealing means for starters



p 1950 R. M. NARDONE 2,503,350

OIL SEALING MEANS FOR STARTERS Filed March 14, 1946 NVE NTOR- HDMEU M.NHHDUNE mesm- Patented Apr. 11, I950 UNHTED STATES PATENT OFFICE OILSEALING S FOR STARTERS Application March 14, 1946, Serial No. 654,409

2 Claims.

The invention relates to starting mechanism for internal combustionengines, and particularly to engine starters of the type in whichstarting is effected by transmission of torque to the engine crankshaftor its equivalent by an axially movable jaw member. The invention isfurther applicable to driving mechanisms of general application outsidethe engine starting art, in which like problems exist. The inventionparticularly relates to provisions for sealing the jaw member againstleakage and for retaining the jaw member in an inoperative positionwhile the engine is running, without interfering with the operation ofthe starter when this turns the engine.

An object of the invention is to provide an improved means for keepingthe jaw member from accidentally moving into engagement with the enginewhile the latter is running. A related object is to provide an improvedsimple assemblage of such means, which assemblage is readily accessiblefor maintenance and replacement purpose.

A further object is to provide means for sealing the engine end of thestarter against leakage of oil which would tend to interfere with theintended functioning of parts of the starter. And still another objectis to adapt such means to proride for the occasional start in whichtheouter end of the starter jaw initially abuts that of the engineinstead of normally meshing immediately, to then permit the necessaryrelative axial movement of parts of the starter to prevent jamming whileat the same time maintaining an adequate seal against oil leakage duringthe short interval in which the stated relative displacement exists.

These and other objects and features of the invention are pointed out inthe following description in terms of the embodiment thereof which isshown in the accompanying drawings. It is to be understood, however,that the drawings are for the purpose of illustration only, and are notdesigned as a definition of the limits of the invention, reference beinghad to the appended claims for this purpose.

In the drawings:

Fig. 1 is a longitudinal sectional view of a starter embodying theinvention; and

Fig. 2 is an end view of a detail, the G-ring for irictionally retainingthe jaw member in its inoperative position while the engine is running.

Referring to the drawings, in which like reference characters indicatelike parts throughout, and particularly to Fig. l, the invention isshown embodied in a starter of the general type shown and described inU. S. Patents 1,962,397 and 2 2,347,788 respectively issued to Lansingand to the instant applicant.

The starter shown herein by way of example includes an electric motor Iconnected by a planetary reduction gearing 2 and a torque limitin unit'3 with the sleeve 4 which is internally threaded at 5 and mounted to berotatableabout the axis of rotation of the starter jaw while it isconstrained against axial movement. A mating externally threadedcup-shaped member 6 is externally splined at 1 to drive a matinginternally splined jaw member 8 at whose outer end are the jaw teeth 9which are adapted to engage the teeth of a complemental jaw, notshown,-on the engine shaft. This arrangement permits the jaw member *8to move axially with respect to the member 6 while these two membersturn relatively, the outward movement of jaw member 8 being stopped whenthe collar surface 6' of member 8 strikes the end 5' of threads 5 ofmember 4 and the inward movement when collar surface 6" of member 6reaches its limit.

Springs 50 bias the members 6 and d awayfrom each other, one end of eachspring to abutting the member 6 and the other abutting a, metal washerit which presses a sealing washer l2 against the inner surface of thejaw member 8 to provide a seal between members t and 8 in spite of therelative axial movement thereof which is necessary when the ends of thejaw teeth strike instead of meshing as they normally do.

Member 6 has a novel male threaded portion it extending toward theengine through a central hole in the jaw member 3, the outer edge of thehole being chamfered at it with, e. g., 70 included angle. A special nutis provided with a cylindrical portion whose inner end abuts a toroidaiseal ring it to prevent leakage between the nut and the stud is. Theouter end of nut it is radially slotted and provided with a cotter pinit to keep it tightl screwed up against the sealing ring iii. The headof the nut 35 is provided with a novel rim which normally seats as avalve against shoulder i l to provide an oil-tight seal there.

Only rarely do the jaw teeth strike on their ends instead of meshing,the result being that this sealing action is only infrequentlyinterrupted and then only very briefly. The centrifugal force due to theturning of the jaw member 8 tends to throw outwardly any oil which mightotherwise tend to enter the hole. Also, the sealing washer i2 acts tokeep such oil out.

The head of nut 15 keeps the jaw member 8 from extending too far towardthe ca. Nut

the end of the starter unit when this unit is detached from the engine.The novel form of nut I5 permits it to be mostly countersunk in the jawmember 8 so as to provide room for the projection on the end of theengine shaft commonly required to secure the mating jaw member thereto.

The housing 18 of the starter unit is provided with a novel oil sealconsisting of the U-shaped flexible ring seal [9 containing the toroidalspring 20 which presses one lip of the seal l9 against the cylindricalportion of the jaw member 8 to prevent oil leakage between the jawmember 8 and the housing I8. This seal I9 lies between Washer 21 and anovel c-ring 22 which is held in place by the outer flange 23 which isriveted to housing l8 by rivets 24. such as Phosphor bronze and is soshaped that, when free, its hole is of the order of one hundredth of aninch smaller in diameter than the cylindrical portion of the jaw member8.

When this seal is assembled, the ring l9 effectively seals the openingbetween the jaw member 8 and the housing [8 against oil leakage and thec-ring 22 strongly tends to hold the jaw member 8 in its last-setposition as long as the jaw member 8 is not turning. The frictionprovided by the novel C-ring 22 is readily made adequate to hold the jawmember 8 in a disengaged position while the engine is running and inspite of such large decelerations as occur during forced landings ofaircraft. This friction also ensures the positive extension of the jawmember 8 during a start.

It is apparent that the several portions of the improved constructionwork together to provide a single unitary article of commerce, a starterjaw assemblage which is oil-tight and also proof against accidentalengagement of the starter with the engine while the latter is running.

Although the present invention is only described and illustrated indetail for one embodiment thereof, it is to be expressly understood thatthe same is not limited thereto. Various changes may be made in designand arrangement of the embodiment illustrated, as will now be apparentto those skilled in the art. For a definition of the limits of theinvention, reference should be had to the appended claims.

What is claimed is:

1. In an engine starter having a first femalethreaded member which ismounted to be turned without axial displacement during starting, asecond mating male-threaded member constructed to move axially of thefirst member upon relative rotation thereto, said second member havingexternal splines upon its jaw end parallel with the aXis of rotation, anannular jaw member The C-ring 22 is of metal having its inner endinternally splined to mate with the splines on the second member andhaving a cylindrical outer surface co-axial with the axis of rotation,and means operatively connecting the second member with the jaw memberto bias the latter outwardly, the improvement comprising the jaw memberhaving a conical seat portion, a threaded portion of said second memberextending through said jaw member and having a nut thereon to limit theoutward movement of the jaw member, said nut having an inverted conicalshoulder adapted to mate with said conical seat portion, means forsealing against leakage between said nut and said threaded portion ofsaid second member, means for sealing against leakage around thecylindrical outer surface of the jaw member, and'a metal C-ring biasedtoward the last-named surface for frictionally retaining the jaw memberin a non-engaging position when the second member is in its innermostposition and the jaw member is not turning.

2. In an engine starter having a first femalethreaded member which ismounted to be turned without axial displacement during starting, asecond mating male-threaded member constructed to move axially of thefirst member upon relative rotation thereto, said second member havingexternal splines upon its jaw and parallel with the axis of rotation, anannular jaw member having its inner end internally splined to mate withthe splines on the second member and having a cylindrical outer surfaceco-axial with the axis of rotatiomand means operatively connecting thesecond member with the jaw member to bias the latter outwardly; theimprovement comprising the jaw member having a conical seat portion, athreaded portion of said second member extending into said jaw memberand having a nut thereon to limit the outward movement of said jawmember, said nut having a shoulder portion adapted to mate with saidconical seat portion to form an oil seal therewith, means for providingan oil seal between said threaded portion and said nut, and means forproviding an oil seal around the cylindrical outer surface of said jawmember.

ROMEO M. NARDONE.

REFERENCES CITED ,The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,019,607 Danver Mar. 5, 19121,720,945 Chryst July 16, 1929 1,965,050 Nardone July 3, 1934 2,412,829Nardone Dec. 17, 1946

